# M.E.L.C. vs 737 Tools · Annunciator Lights

The clearest difference is price: M.E.L.C. at Free against 737 Tools · Annunciator Lights's $9.99. M.E.L.C. also leads on iOS requirement (13.0 vs 15.0). 737 Tools · Annunciator Lights's advantage is in-app purchases (none vs 1) and update cadence (every 6 weeks vs every 18 months). On ads and device support there is nothing between them.

M.E.L.C. is free to download; 737 Tools · Annunciator Lights costs $9.99 up front. M.E.L.C. sells 1 one-off in-app purchase. 737 Tools · Annunciator Lights asks for nothing beyond the download.

M.E.L.C. ships an update every 18 months, 737 Tools · Annunciator Lights every 6 weeks. The most recent releases landed on November 4, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | M.E.L.C. | 737 Tools · Annunciator Lights |
| --- | --- | --- |
| Price | **Free** | $9.99 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/melc/id1315299613/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 18 months | **Every 6 weeks** |
| Monetization | Free | — |
| Size | 6 MB | 60 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPod, Apple Watch | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Janko Enke](https://appshunter.io/developer/1315299612) | [Adria Raventos ruiz](https://appshunter.io/developer/1876663356) |

## What reviewers say

### M.E.L.C.

[App page](https://appshunter.io/ios/app/melc/id1315299613)

This tool helps aircraft engineers calculate the expiration dates for airplane defects based on minimum equipment lists. It provides a clear overview of all critical dates and allows for customization of defect categories.

**Highlights:** Calculate defect expiration dates, Supports categories A, B, C, D, View all important dates at a glance, Customize defect categories

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full version | $0.99 | one-time |


### 737 Tools · Annunciator Lights

[App page](https://appshunter.io/ios/app/737-tools-annunciator-lights/id6794879293)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is M.E.L.C. free?

M.E.L.C. is free to download, with in-app purchases available.

### Is 737 Tools · Annunciator Lights free?

737 Tools · Annunciator Lights costs $9.99, with no in-app purchases.

### Do M.E.L.C. or 737 Tools · Annunciator Lights have ads?

Neither M.E.L.C. nor 737 Tools · Annunciator Lights shows ads.

### Which is updated more often, M.E.L.C. or 737 Tools · Annunciator Lights?

M.E.L.C. ships an update every 18 months, and 737 Tools · Annunciator Lights every 6 weeks. Most recently, M.E.L.C. was updated on November 4, 2026 and 737 Tools · Annunciator Lights on November 8, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*